To the editor: Advanced renal insufficiency requiring hemodialysis other than acute tubular necrosis may be totally or partially reversed in certain diseases. 1 More effective and aggressive treatment may be able to improve prognosis of conditions such as autoimmune, 2-4 tumoral,5,6 and even cardiovascular diseases.7,8 Some of these conditions were doubtfully amenable to renal replacement therapy until recently. In this group of new diseases admitted for hemodialysis, relative recovery of renal function may be seen without this involving discontinuation of such treatment in all cases. Our experience is briefly summarized below.



The first case reported is a 56-year-old male recently diagnosed of IgA multiple myeloma with plasma cell infiltration of 27%. He was referred to us with laboratory data suggesting advanced renal insufficiency (ClCr 7 mL/min, Cr 8.3 mg/mL) and no apparent signs of hemodynamic decompensation, hypercalcemia, or nephrotoxics. `Dialysis and simultaneous specific treatment for his underlying disease were immediately started. Three months after the first dialysis session, the patient has serum Cr levels of 2.36 mg/dL.



The second case was a 16-year-old female who attended the emergency room for a general syndrome of fatigue and anorexia, and reported a pharyngeal process in the previous days. Serum Cr levels were 10 mg/dL, and dialysis was therefore started. Laboratory tests suggested glomerulonephitis, and renal biopsy confirmed the presence of endocapillary and extracapillary proliferation with 50% of cell crescents. Corticosteroid and cyclophosphamide were administered as a bolus. Serum Cr levels of 1.4 mg/dL were found at 15 days.



The third case was an 83-year-old male patient admitted for fatigue who was found advanced uremia (Cr 5.8mg/dL) and clinical and biological evidence of rapidly progressive glomerulonephritis. No renal biopsy was performed because of the patient age and poor cooperation. He was treated with corticosteroid and  cyclophosphamide boluses. After 6 months on hemodialysis, serum creatinine value was 3.5



mg/dL, and session time was shortened. A fourth, more complex case was that of a 64-year-old male patient with a history of alcohol-induced cirrhosis and moderate renal insufficiency who was admitted in a state of overshoot uremia. He underwent regular hemodialysis and recovered a certain renal function, but total withdrawal from replacement therapy was not considered appropriate because of his initial severe status and the great improvement in his quality of life.



Finally, regular hemodialysis for refractory heart failure was started in a 67-year-old male patient with Cr levels of 6 mg/dL. He had been diagnosed dilated cardiomyopathy based on echocardiographic data. Since hemodialysis was started 16 months ago, the patient has not required any hospital admission, performs a normal physical activity,

and has substantially recovered renal function. Hemodialysis discontinuation is not considered appropriate.



While it is true that our patients could be considered in some case potentially recoverable, considering the severity of the baseline condition and/or underlying disease, no statement could be made a priori. Special mention should be made of the improved quality of life and absence of hospital admissions once replacement therapy was started. The indication for monitoring of residual function is emphasized.9,10